This application claims priority to Swedish Application No. 0001 920-8, filed May 23 2000.
1. Technical Field
The present invention relates to an internal combustion engine installation in a motor vehicle. More specifically, the present invention relates to an internal combustion engine arranged in an engine compartment, with the engine having an intake air conduit that opens to an intake manifold, and an exhaust manifold that opens to an exhaust conduit.
2. Background Information
The development of new engines for vehicles has been directed for quite some time to increasing the engine efficiency in order to, inter alia, reduce the amount of exhaust and its damaging effects to the environment. Catalytic converters are typically used to reduce the percentage of damaging substances in vehicle exhaust. It is also known to use a hydrocarbon absorbent, e.g., a zeolite, between the exhaust manifold and the catalytic converter to take care of the hydrocarbons before the catalytic converter has become sufficiently hot. Also, combined electric and internal combustion engines, called hybrid engines, have come into commercial use as a means for reducing the amount of exhaust released from engines.
Lately, however, methods have been developed to clean the air already polluted by other vehicles, including breaking down toxic ozone found close to the ground. This ozone is formed by photosynthesis of hydrocarbons and nitrogen oxides, i.e., the smog formed when these substances from vehicle exhaust are subjected to sunlight. In a known method, a catalytic coating is sprayed onto the radiator flanges and pipes of the vehicle. When the ozone comes in contact with the heated catalytic converter coating, it is transformed into oxygen.
The present invention intends to achieve an engine installation which makes it possible to remove additional toxic substances in ambient air, such as existing hydrocarbons from the exhaust of other vehicles.
This is achieved according to the invention by arranging a hydrocarbon-absorbing element and a heating device relative to each other in an engine compartment so that a portion of the hydrocarbon-absorbing element is exposed to the surrounding engine compartment when another portion of the element is exposed to the heating device. In such manner, by heating the portion of the hydrocarbon-absorbing element with the heating device, hydrocarbons from ambient air that are absorbed by the hydrocarbon-absorbing element are removed from the element. The hydrocarbon-absorbing element is movable in such manner that a portion of the element is able to move to the heating device at the same time as another portion moves away from the heating device.
The hydrocarbon-absorbing device can be a zeolite with a honeycomb structure, or an active carbon filter that absorbs hydrocarbons in ambient air. After a certain time, such a device becomes saturated with hydrocarbons and needs to be regenerated, i.e., have the absorbed hydrocarbons removed. This is done by heating the device, thereby enabling the hydrocarbons to be desorbed. Once desorbed, they are sucked into the engine combustion chambers and combusted. The hydrocarbon-absorbing element can be a disc that is rotatable by the engine. The disc may be rotated stepwise after a certain time period, e.g., every ten minutes, so that a new sector of the disc is rotated into the heating device and regenerated while the rest of the disc is exposed to ambient air flowing into the engine compartment.